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<title>pthread_attr_setschedpolicy</title>
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The Single UNIX &reg; Specification, Version 2<br>
Copyright &copy; 1997 The Open Group

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<h4><a name = "tag_000_007_1162">&nbsp;</a>NAME</h4><blockquote>
pthread_attr_setschedpolicy, pthread_attr_getschedpolicy
- set and get schedpolicy attribute
(<b>REALTIME THREADS</b>)
</blockquote><h4><a name = "tag_000_007_1163">&nbsp;</a>SYNOPSIS</h4><blockquote>
<pre><code>

#include &lt;<a href="pthread.h.html">pthread.h</a>&gt;

int pthread_attr_setschedpolicy(pthread_attr_t *<i>attr</i>, int <i>policy</i>);
int pthread_attr_getschedpolicy(const pthread_attr_t *<i>attr</i>, 
    int *<i>policy</i>);
</code>
</pre>
</blockquote><h4><a name = "tag_000_007_1164">&nbsp;</a>DESCRIPTION</h4><blockquote>
The functions
<i>pthread_attr_setschedpolicy()</i>
and
<i>pthread_attr_getschedpolicy()</i>,
respectively, set and get the
<i>schedpolicy</i>
attribute in the
<i>attr</i>
argument.
<p>
The supported values of
<i>policy</i>
include SCHED_FIFO, SCHED_RR and SCHED_OTHER,
which are defined by the header
<i><a href="sched.h.html">&lt;sched.h&gt;</a></i>.
When threads executing with the scheduling policy
SCHED_FIFO or SCHED_RR are waiting on a mutex,
they acquire the mutex in priority order when the mutex is unlocked.
</blockquote><h4><a name = "tag_000_007_1165">&nbsp;</a>RETURN VALUE</h4><blockquote>
If successful, the
<i>pthread_attr_setschedpolicy()</i>
and
<i>pthread_attr_getschedpolicy()</i>
functions return zero.
Otherwise, an error number is returned to indicate the error.
</blockquote><h4><a name = "tag_000_007_1166">&nbsp;</a>ERRORS</h4><blockquote>
The 
<i>pthread_attr_setschedpolicy()</i>
and
<i>pthread_attr_getschedpolicy()</i>
functions will fail if:
<dl compact>

<dt>[ENOSYS]<dd>
The option _POSIX_THREAD_PRIORITY_SCHEDULING is not defined and the
implementation does not support the function.

</dl>
<p>
The
<i>pthread_attr_setschedpolicy()</i>
function may fail if:
<dl compact>

<dt>[EINVAL]<dd>
The value of the attribute being set is not valid.

<dt>[ENOTSUP]<dd>
An attempt was made to set the attribute to an unsupported value.

</dl>
</blockquote><h4><a name = "tag_000_007_1167">&nbsp;</a>EXAMPLES</h4><blockquote>
None.
</blockquote><h4><a name = "tag_000_007_1168">&nbsp;</a>APPLICATION USAGE</h4><blockquote>
After these attributes have been set, a thread can be created with
the specified attributes using
<i><a href="pthread_create.html">pthread_create()</a></i>.
Using these routines does not affect the current running thread.
</blockquote><h4><a name = "tag_000_007_1169">&nbsp;</a>FUTURE DIRECTIONS</h4><blockquote>
None.
</blockquote><h4><a name = "tag_000_007_1170">&nbsp;</a>SEE ALSO</h4><blockquote>
<i><a href="pthread_attr_init.html">pthread_attr_init()</a></i>,
<i><a href="pthread_attr_setscope.html">pthread_attr_setscope()</a></i>,
<i><a href="pthread_attr_setinheritsched.html">pthread_attr_setinheritsched()</a></i>,
<i><a href="pthread_attr_setschedparam.html">pthread_attr_setschedparam()</a></i>,
<i><a href="pthread_create.html">pthread_create()</a></i>,
<i><a href="pthread.h.html">&lt;pthread.h&gt;</a></i>,
<i><a href="pthread_setschedparam.html">pthread_setschedparam()</a></i>,
<i><a href="sched.h.html">&lt;sched.h&gt;</a></i>.
</blockquote><h4>DERIVATION</h4><blockquote>
Derived from the POSIX Threads Extension (1003.1c-1995)
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UNIX &reg; is a registered Trademark of The Open Group.<br>
Copyright &copy; 1997 The Open Group
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